The present disclosure relates to sheet feeders used for stocking in advance multiple sheets, such as paper, to be supplied to a device, and image forming apparatuses including such a sheet feeder.
Paper feed cassettes are used for feeding paper, such as cut paper, etc. in image forming apparatuses typified by copiers and printers. A paper feed cassette stocks multiple pieces of non-printed paper in advance and separates and feed it on a sheet-by-sheet basis from the topmost sheet of the paper sheaf stacked in the cassette.
Some paper feed cassette is provided with a sheet loading plate having an upper surface on which paper is to be loaded. The sheet loading plate is supported at its upstream end in a paper feed direction on the inner bottom surface of the cassette main body so that its downstream end in the paper feed direction is turnable as a turning end about the support point as a center. The turning end of the sheet loading plate is lifted upward by a drive means, such as a lift motor or an urging means, such as a spring provided in an image forming apparatus. Thus, the downstream end of the paper loaded on the sheet loading plate can be moved to an appropriate feed position, thereby achieving stable paper feed.
As describe above, the sheet loading plate is supported at its upstream end in the paper feed direction so that its downstream end is turnable as a free end about the support point as a center. Accordingly, the sheet loading plate may turn and float upward by inertia in fitting the paper feed cassette to the image forming apparatus or vibration and/or impact in abutting the paper feed cassette on the insertion point in the rear side of the image forming apparatus. This may cause paper accommodated in the paper feed cassette to flip up toward the downstream side in the insertion direction.